1. Field of the Invention
This specification relates to an integrated interlock device of an air circuit breaker, and a method of using the same, and more particularly, to an integrated interlock device of an air circuit breaker capable of using different types of interlock devices in an integrated manner in case of using two or more air circuit breakers connected to each other, and a method of using the same.
2. Background of the Invention
Generally, an aft circuit breaker is a kind of circuit breaker configured to open and closes a load at a power transmission site or a substation, or on an electric circuit, etc., or configured to cut off a current when an accident such as a ground connection (earthing) or a short-circuit occurs, and is mainly used for a low voltage device.
Such an air circuit breaker may be used in a state where two or more air circuit breakers are connected to each other for interaction. In this case, it is required to control an interaction of the plurality of air circuit breakers. For example, if a first circuit breaker is turned on, a second circuit breaker is turned off. Such an interaction may be extended to three or more air circuit breakers. As such an interaction, a method of controlling on-off operations of two or more circuit breakers by using cables has been widely used.
A door lock function may be provided to prevent a switchboard door from being open while a circuit breaker is being operated. Such a door lock function may be also performed by utilizing cables, if a switchgear door and a circuit breaker are far from each other.
However, in case of such an interlock device using cables, either a mechanical interlock or a switchboard door interlock should be selectively used.
For example, U.S. Pat. No. 6,225,581 ‘Installation comprising an Electrical Switchgear Apparatus and a Cable Interlock’ may be referred to. A prior art thereof is shown in FIG. 1. The prior art relates to an apparatus in which a switching mechanism of one or more circuit breakers is interlocked with a mechanical interlock or a door by a power transmission cable.
This prior art includes a circuit breaker (not shown), a cable 138 and an interlock means 130. Here, the cable 138 is composed of a sheath 182 formed of a flexible material, and a core 186 slidable in the sheath 182. One end of the sheath is fixed to a frame 122 by a fixing means 120, and one end of the core 186 is fixed to the interlock means 130. The interlock means 130 includes an end part 194 that operates by interworking with a cable, and a housing 104 that accommodates the end part therein.
The interlock means 130, the fixing means 120 and the cable 138 are installed at a cradle (not shown) of one circuit breaker (first circuit breaker) in a connected state to each other, and installed at a cradle (not shown) of another circuit breaker (second circuit breaker) with a symmetric structure for interaction. That is, if the cable 138 is pulled as the first circuit breaker is turned on, the second circuit breaker is turned off by the pulled cable.
Such an interlock device connected to two circuit breakers is usually installed in a pair. Assuming that the above device is ‘A’, the same or similar device ‘B’ is installed close to the A. Here, the ‘B’ may be installed to perform an operation in an opposite direction to the ‘A’. According to the ‘B’, when the second circuit breaker is turned on, the ‘on’ operation is transmitted to the first circuit breaker by a cable so that the first circuit breaker is turned off.
However, the conventional interlock device is configured to perform only one function of a mechanical interlock at two circuit breakers connected to each other. Even though such a function may be used by being converted into a door lock function, only one function may be performed.
In order to overcome such limitations, has been proposed an invention capable of using different interlock functions in an integrated manner. For example, Korean Patent Laid-Open No. 10-2016-0037619 ‘Interlock device for air circuit breaker’ may be referred to. A prior art thereof is shown in FIG. 2. The prior art relates to an interlock device of an air circuit breaker capable of simultaneously performing a mechanical interlock function and a door interlock function.
The prior art includes a rotation pin 210 connected to a main shaft of an air circuit breaker and rotated according to a closing or interrupting operation of the circuit breaker; a first lever 220 having one end where a locking groove 221 for inserting the rotation pin 210 is formed such that the first lever 220 performs a rotary motion by the rotation pin 210, and having another end to which a first wire 230 is connected; a slider 250 installed to be spaced apart from the first lever 220, and connected to a second wire 235 to receive a force when another air circuit breaker performs a closing operation; and a lock member 270 coupled to a rotation shaft 222 of the first lever 220, and locked to a hooking member 285 provided at a switchboard panel door 280.
In the prior art, when the main shaft of a first circuit breaker is operated on an ‘on’ position, the rotation pin 210 is rotated about the main shaft and the first lever 220 is rotated by interaction. As a result, the lock member 270 installed at the rotation shaft 222 is rotated to restrict the switchboard panel door 280. On the other hand, when a second circuit breaker is operated on an ‘on’ position, the ‘on’ operation is transmitted through the second wire 235 to pull the slider 250 and to cause the first circuit breaker to be turned off by an operation lever 240 connected to the slider 250. Such a configuration is similar to the aforementioned prior art.
In summary, in the prior art, a mechanical interlock is carried out by using a cable, and a door lock function is carried out by a lock member separately installed at a rotating lever.
However, in the prior art, since a mounting plate 215, the switchgear panel door 280 and the lock member 270 should be connected to each other, there is a spatial limitation and the degree of freedom of design is reduced. In addition, an additional configuration different from a configuration using a cable should be implemented, an entire configuration becomes complicated.
Thus, it is necessary to use a plurality of interlock functions used at a circuit breaker such as a mechanical interlock function or a switchboard door interlock function, in an integrated manner.